Paper lock



Dec. I1; 1923. 1,476,822

. I F. KRONENBERGER PAPER LOCK Filed Aug. 22 1921 2 Sheetq-Sheet 1 INVENTOR firdmand Arme/lberger j ATTORNEY Patented Dec. 11, 1923.

UNITED STATES rnanmannxaonnmsnaena,or New YORK, N. Y.

rarna Loox.

Application filed August 22, 1921. Serlal'11'o. 494,316.

To all whom it may concern:

Be it known that I, FERDINAND KRoNEN- BERGER, a citizen of the United States, and resident of the city of New York, in the county of Queens and State of New York, have invented certain new and useful Improvements in Paper Locks, of which the following is a. specification.

This invention relates to closures for paper boxes and is especially applicable to sealing flaps.

1 One of the objects of this invention is the provision of a simple paper lock which is formed entirel from the parts of the box or envelop and w ich automatically snaps into place on the ompletion of the locking movement.

A. further object of this invention isthe provision of means for quickly and easily fastening a flap into place, in which means the parts cannot be separated unless they are destroyed. I

A further object of this invention is the 'provision of a box closure which, while acts ing as an effective seal, dispenses with the necessity for adhesives or extraneous fastenings.

A still further object of this invention is the provision of a box closure in which side-v wise manipulation of the parts is prevented. @ther objects will appear as the description progresses. In the drawings accompanyin this specification, 1 is a front view 0 my improved lock. ig. 2 is a vertical section of the same on the line 2-2 of Fig. 1. Fig. 3 is a front view of the tab member and Fig. 4 is a. similar view of the receiving or slitted member. Fig. 5 is a front view of a modified form of my inven tion. Fig. 6 is a'vertical section of the same on the line 66 of Fig. 5. Fig. 7 is a front view of the slitted member of the lock shown in Fig. 5. Fig.8"i's-a similar view of the tab member. Fig. 9 is a front view of a box blank to which my improved lock hasbeen applied. Fig. 10 is a perspective view of a box made from the blank, and Fig. 11 is a similar view of a similar box in which the lock shown in Fig. 5 is used.

' I lt willbe seen that two types of my improved lock'are shown in the drawings. In" one type, the movable member, that is, the

flap to be locked, is partly slitted and formed substantially into a tab, and the re- 1. ceiving member or stationary box part into which the tab isinserted, isslitted suficiently to receive the entire tab throughout the width thereof, inclusive of the slitted alswill therefore be used to designate similar arts on each. I

T e tab portion 10 of the lock is preferably rounded or bevelled at the free extremity thereof for easy insertion into a suitable slit, and has cut therein a'pair of slits 11 extending inwardly from the edges of the tab" toward each other for any deslred distance. i

The slit, 13 into which the tab 10 is to be inserted, is made by a suitable cut in the paper and is of substantially the same length asthe distance between the outer extremities of the slits 11, and, of course, is of less length than the width of the member in WhICh it is cut. It willbeseen that shoulders as 14 are formed on one side of the slits .11, while the shoulders 15.are formed on the other side thereof.

In order to lock the parts together, the tab 10 is pushed into the slit 13 until the shoulder portions 15 have passed completely through the said slit 13, whereupon the parts become firmly locked together and cannot be withdrawn withoutdamage thereto, as will now be explained in detail. On the insertion of the tab 10 into the slit 13 of the receiving member 16, that portion 17 of the receiving member on one side of the said slit 13 and outside of the inserted tab 10' is sprung, outwardly from the original plane and tends to press the shoulders 15 inwardly,

the extremities of saidshoulders being free to move when unsupported, by reason of the separating slits 11. The inwardly sprung portion 1 8 similarly tends to straighten out into its original position and therefore trans- I mitsthe outward pressure on to the shoulders 14 of the tab 10. From the above it will be clear that during the operation of inserting'thetab into the slit provided therefor, the shoulders 15 are pressed inwardly, while the shoulders 14 are pressed outwardly or in the opposite direction, whereby said shoulders tend to become separatedsin the direction of the paper thickness.

At the moment, however, that the insertion of the shoulders 15 throughthe ,slit 13 is completed, said shoulders being no longer supported by the portion 18 of the receiving member, automatically snap inwardly, while the said portion 18 tends to straighten out in an outward direction and hence comes into close contact with the inner surface of the shoulders 14. The lateral movement of the shoulders 15, and of the portion 18, though slight, is sufficient to bring the free extremities of Said shoulders into contact with the edge of the portion 18, so that the edges of said shoulders and said portion abut one against the other for a substantial part of each edge, and lie approximately in the same plane. Any attempt now to Withdraw the tab 10 from the slit 13, is resisted by the abutting edges of the shoulders 15 and the portion 18, whereby the parts cannot be separated without tearing said shoulders or said portion 18. Similarly, the slitted edges of the shoulders 14 are pressed outwardly and contact with and abut against the slitted edge 17, whereby further insertive movement of the parts is prevented. It

will be noted that, in distinction from the usual tab and slit lock, no paper is cut away at the shoulders 14 and 15, but that dependence is placed on the spring action of said,

shoulders, as has been pointed out above.

In that form of my lock shown in Figs. 5, 6, 7, 8 and 11, the slit 13 is cut in the movable member such as a box flap 16, while a stationary part of the box such as the receiving member- 19 or the box front 20 has the tab member 10 cut therein, as by means of the side cuts 12, whereby the lock is reversed in position, while the operation thereof remains exactly the same as in the other type. Said side cuts 12' are made of suificient length to allow the passage thereunder of the movable fiap to a point at which the locking operation above described can take place.

In the application of my improved lock to a. box such as the eggcarton 21, means are provided for maintaining the lock parts in the locked position thereof, whereby the unlocking of the said parts by sidewise manipulation is prevented. In addition to providing a double lock 23, I provide a preferably corrugated reinforcing flap 24 folded under and secured to the under side of the box cover 25, the edges 26 of said flap being bevelled at an angle of 45 degrees, as shown in the blank 27 (Fig. 9), and a second flap 28 integral with the box front and bent approximately at right angles thereto, said flap 28 being bevelled at the edges 29 thereof, similarly to the edges 26. \Vhen the lock is fastened in place, each of the edges 26 comes into contact with and abuts against the adjacent edge 29, since the flaps 24 and 28 lie substantially in the same plane. It will therefore be seen that movement of the cover 25 relatively to the box body in a sidcwise direction is prevented, whereby the lock is maintained in its locked position, and the box is effectively sealed without the use of adhesives or other extraneous fastenings of metal or other material.

I claim:

1. A closure comprising a flap having slits severing the material of said flap and directed inwardly from the edges thereof, and a receiving member having a slit cut therein substantially equal in length to the width of said flap at the slitted part thereof.

2. A closure comprising a partly slitted member comprising a tongue portion and a body portion immediately adjacent to and severed from said tongue portion, and a. second member slitted to receive. said first mentioned member in such a. manner that the edge of the slit in the first member contacts with a slitted edge in said second member.

3. A closure comprising a tab having slitformed shoulders and a body portion severed from and at least as wide as said tab, and a slitted receiving member, said tab being adapted to be inserted in the slit of said receiving member to a point where said shoulders of said tab member abut against the slitted edge of said receivin member whereby relative movement of sai flap and said receiving member is prevented.

4. A closure comprisin a flap, bendable shoulder portions formed by slits severing the material of said flap and directed inwardly toward each other from the edges of said flap, and a receiving member having a slit cut therein parallel to the slits in said flap and of sufiicient length to receive said flap together-with the slit formed shoulder portions thereof, said flap bein adapted to be inserted into the slit of said receiving member for a sufiicient distance to allow the edges of the shoulder portions of said flap and the edges of the slit in said receiving member to automatically snap into abutting relation.

5. In a box, the combination of a box front member, a lip on the upper edge of said front member integral with and bent from said front member substantially at right angles thereto, bevelled ends on said lip, a cover member, a reinforcing flap gummed to the under side of said cover, bevelled ends on said reinforcing flap, a partly slitted locking flap on one of said members, and slit-formed edges equal in length to the width of said flap at the slits thereon on the other of said members, said flap being adapted to enter between said slit-formed edges for locking said flap, and the adjacent bevelled corners of said lip and said I'Gil'lfOl'CiIlg flap being adapted to engage for maintaining said flap in the locked position thereof.

6. In a box, the combination with a box front and a movable flap, of means for locking said flap to said front and means for locking said flap against sidewise! movement of the locking means eomprisin a lip inte ral with and bent from sai front, beveiled ends on said lip, a reinforcing flap secured to the under side of said movable flap, and bevelled ends on said reinforcing flap adapted to engage the bevelled ends on said lip, in the locked position of said movable flap.

7. In a box, a tab having slit-formed edges extending inwardly toward each other and a body portion severed from said tab by said slits and at least as wide as said tab, a tab receiving member having slitformed edges adapted to engage the slit formed edges of said tab, and means on said box for preventing sidewise movement of said slit-formed edges.

8. A paper lock comprising a tab, a slitted member adapted to receive said tab, and shoulders on said tab free at one extremitythereof and adapted to automatically snap into abutting edge contact with said slitted member on the completion of the insertive movement-of said tab into the slit of said slitted member, a body portion substantially wider than said tab and partly severed from said tab, and shoulders on said'body portion immediately adjacent to and of the same length as the shoulders on said tab.

9. A paper lock comprising a slitted receiving member, a second member, a tab formed from the body of said second mem ber by means of severing cuts therein, and severing slits in said tab directed inwardly toward each other from the tab forming cuts.

Signed at New York, in the county of New York and State of New -York, this 19th day of August, A. D. 1921.

FERDINAND KRONENBERGER; 

